Add README with instructions on how to run renovate

.ls-lint.yml

@@ -18,3 +18,5 @@ ignore:
   - node_modules
   - SECURITY.md
   - test/e2e/node_modules
+  - config.example.js
+  - README.md

README.md

@@ -0,0 +1,44 @@
+# Commodore Renovate Support
+
+This repository builds [renovate](https://github.com/renovatebot/renovate/) with added support for [Commodore](https://github.com/projectsyn/commodore).
+It does this by depending on renovate and patching in an additional manager for Commodore.
+
+## Development
+
+### Prerequisites
+
+You need the following dependencies for local development:
+
+- Git `>=2.33.0`
+- Node.js `>=14.15.4`
+- Yarn `^1.22.5`
+- C++ compiler
+- Python `^3.9`
+
+### Run
+
+To run the extended renovate against a real repository, you first need to configure it.
+Renovate can be configured through command-line flags, environment variables, or through a `config.js` at the root of the repository.
+
+We provide an example configuration to renovate a single repository on a private Gitlab instance in `config.example.js`.
+You can copy and update this example configuration.
+You will always need a valid platform token.
+
+There is a list of configuration options as part of the [official renovate docs](https://docs.renovatebot.com/self-hosted-configuration/#repositories).
+
+With a valid configuration you can now run the extended renovate with:
+
+```
+yarn dev
+```
+
+### Tests
+
+You can run `yarn test` locally to test your code.
+We test all PRs using the same tests, run on GitHub Actions.
+
+### Linting and formatting
+
+We use [Prettier](https://github.com/prettier/prettier) to format our code.
+If your code fails `yarn lint` due to a `prettier` rule then run `yarn prettier-fix` to fix it.
+You usually don't need to fix any Prettier errors by hand.

config.example.js

@@ -0,0 +1,12 @@
+module.exports = {
+  endpoint: 'https://git.company.net/api/v4/',
+  token: 'YOUR_GITLAB_TOKEN',
+  platform: 'gitlab',
+  onboardingConfig: {
+    extends: ['config:base'],
+    prConcurrentLimit: 5,
+  },
+  repositories: ['youraccount/yourrepo'],
+  enabledManagers: ['commodore'],
+  dryRun: 'true',
+};